It seems like decades have elapsed since we first announced we'd be taking part in the Castrol Syntec Top Shop Challenge. As the name suggests, it's sponsored by Castrol's leading Syntec lubricant and they challenge et, plus six other magazines within our group, to an engine war.
Last month you would have read how our chosen champions, 034 Motorsport in Fremont, CA had taken our Audi 80 2.3 liter 20v engine one step closer to victory. To recap, the 20v has a fully built bottom end, special heads, massive 1250cc injectors feeding the turbo mounted on an 034 stainless steel header. Passing through a huge intercooler and gaping throttle body, the air and fuel is ignited by the 034EFI stage IIc engine management system that control the sparks.
Last month, the team at 034 Motorsport (www.034motorsport.com) were able to run a 60mm wastegate to control the boost curve at around 40psi. By rigging the engine into its Audi 80 and running it on their chassis dyno they attempted to simulate the conditions the engine would experience on the engine dyno in the competition.
Under these jerry-rigged conditions the engine kicked out 760hp at the wheels, and 560 lb-ft of torque using 120-octane. After experimenting with timing, boost and turbo size, they eventually settled on the GT42RS turbo over the larger GT45 because it made more power under the curve - an important judging criteria in the Challenge. Running on the regulation 100-octane, this set up netted 703whp at 8800rpm on 36psi.
According to Javad Shadzi from 034, the biggest factor was 100-octane fuel. Trying to make so much power on a lower octane than we'd normally use took far more tuning than normal. This is now probably the best motor I've ever built because we've had to stretch ourselves to make this octane work. We've definitely pushed the engine as far as it'll go on boost and timing. We're actually making more power on less boost because of the octane. He revealed. "As we raised the boost, we've had to raise timing to the point where we're almost approaching 0 - we're running about 8 at peak power, which isn't a lot for this sort of motor."In the continuous bid for reliability, 034 has installed vacuum pump on the motor. They report it pulls up to 10 of vacuum at 4000rpm and holds 5 to redline.
The advantage of a vacuum pump is it protects the motor from crankcase pressure and helps the piston rings seal against the cylinder walls by sucking out the pressure the boosted engine creates. "It took as a while to finalize the setup," Javad explained. "We had to experiment with it and are now running two oil catch cans to trap the oil that's inevitably sucked out of the crankcase by the pump, returning it to the sump. But it should be worth it as this sort of pump can typically gain 20-30hp."Another of Javad's ingenious devices is the air-to-water intercooler (chargecooler). It's required because the engine obviously won't be getting sufficiently airflow while sat in the dyno room, so a conventional intercooler would be useless. The 034 solution was to install a chargecooler on the engine. The air passing through it is cooled by a continuous flow of water. And to keep the water cool they installed heat exchangers in a Walmart cooler box filled with ice. Using a flow of regular tap water through cooler, they expect to drop inlet temps from 250 to around 40-50F. If this doesn't work sufficiently, they have the option of using dry ice in the cooler as well.